Comparative Study of Harmonic Analysis in Different Levels of Symmetrical Cascaded H-bridge Multilevel Inverter for Photovoltaic System

Photovoltaic energy conversion becomes main focus of many researches due to its promising potential as source for future electricity and has many advantages than the other alternative energy sources like wind, solar, ocean, biomass, geothermal etc. In Photovoltaic power generation system multi level inverters can be used as an alternative configuration for the dc to ac inverter. Diode clamped inverter, Cascaded H-bridge inverter and Flying capacitor inverter are the three widely used configurations of multilevel inverters .Among these three configurations, Cascaded H –bridge multilevel inverter is mostly used for photovoltaic system because each cell of Cascaded H –bridge multilevel inverter requires separate DC sources which can be easily supplied by individual PV arrays and each H-Bridge cell will be available in a single module . This research paper deals with a comparative study of harmonic analysis in different levels of Symmetrical Cascaded H –bridge multilevel inverter employing multicarrier pulse width modulation technique for photovoltaic system. From this study it is found that the total harmonic distortion is low for higher levels of Symmetrical Cascaded H –bridge multilevel inverter and hence the efficiency of the system will be improved . The harmonic contents in output voltage and load current has been analyzed upto 7 harmonics in different levels of symmetrical cascaded h-bridge multilevel inverter and has been studied by the MATLAB/Simulink. The simulated output shows very favorable results.